Wounds usually occur when there is trauma to the skin and underlying tissue. Types of trauma include lacerations, abrasions, incisions, punctures, and penetrations. After trauma, the wound begins to heal in a complex series of biochemical processes occurring in several wound-healing phases. The phases of healing are often categorized into a hemostasis phase, an inflammatory phase, a proliferative phase and a remodeling phase. In hemostasis, active bleeding is controlled by clotting. In the inflammatory phase, pathogens are removed by the body away from the wounded area, and biological factors are released (which later cause the division of cells involved in the proliferative phase). In the proliferative phase, new blood vessels are formed and wound contraction occurs. Also in the proliferative phase, epithelial cells cover the wound, providing an area of growth for new tissue. During contraction, the wound is made smaller by myofibroblasts attaching to the wound edges, and finally, during the remodeling phase, collagen fibers are realigned along tension lines formed during the earlier phases of healing.
Not only is the process of wound healing complex, it is also fragile because many factors can lead to a disruption of proper wound healing, including re-injury of the tissue, bacterial infection, and physical stress on the damaged tissue. A variety of devices and methods have been used to aid in the wound healing process. These devices and methods are generally divided into one of three types: primary intention, secondary intention, and tertiary intention. The primary intention devices and methods bring the edges of the wounds together, so that the edges are reapproximated. Reapproximation helps to minimize scarring, and increases the speed at which wound contraction and healing occur. Examples of primary intention devices and methods include the use sutures, staples, tape, glue, and hooks. Primary intention techniques to heal wounds are the most common techniques used by practitioners.
While not as commonly used, secondary intention devices and methods include first allowing the wound to first granulate without closing the wound. The wound is packed and drained, often daily, to remove debris and encourage granulation tissue formation. Still less common are tertiary intension devices and methods, which delay the closure of the wound even longer, so that the practitioner can close the wound at a later time. Tissue grafting is an example of a tertiary method for wound healing.
Wound edge reapproximation is key to wound healing. If the edges of the wound are not immediately reapproximated soon after injury, healing may be delayed. This delay in healing may leads to scarring and infection. While in some circumstances a delay is advantageous, practitioners generally want to close an open wound as soon as possible.
The traditional method to reapproximate wound edges is by sutures, where a practitioner stitches a threading material to connect opposing sides of a wound. Sutures and suturing techniques are well known in the prior art, such as described by Fallman in U.S. Pat. No. 8,267,959. Other devices and methods to reapproximate wound edges include hooking devices, such as the hook closure device disclosed by Bargon in U.S. patent application Ser. No. 13/266,825, where a band placed over a wound has a multiplicity of hook elements that engage a mesh on the opposing side of a wound.
The use of adhesive strips is another method to aid in wound closure. In U.S. Pat. No. 4,825,866 to Pierce, adhesive strips are placed on opposite sides of a wound and drawn together to reapproximate the wound edges. Stapling and clipping the edges of wound are other techniques to reapproximate wound edges, as described by Zadno in U.S. Pat. No. 7,556,632.
The use of magnets to reapproximate wound edges also has been previously described. U.S. patent application Ser. No. 10/512,964 to Wheatley and U.S. Pat. No. 9,402,605 to Viola are two applications that have described tissue-joining devices comprising interconnecting components where the magnetic components are attracted to each other and draw tissue together using magnets attached to a patient's skin. Flexible magnetic devices have improved the ability to place magnets on wounds where either the wound itself is non-linear or where the wound is located on a curved surface. U.S. Pat. No. 9,486,217 to Moustafa discloses the use of flexible magnets to reapproximate wound edges that are non-linear or on a curved surface.
Other compositions and methods to reapproximate wound edges include the use of medical adhesives, such as cyanoacrylate glues that provide for very tight, high-strength closure of wounds without the need for the physical closure accomplished with sutures. However, cyanoacrylate based glues have been associated with the formation of toxic byproducts, and even non-toxic versions are generally only useful for smaller, shallow lacerations in low-tension areas. These adhesives can be very unforgiving if the practitioner needs to remove the glue. Another disadvantage of using glues for wound closure is that leakage of glues can cause serious ramifications, especially if the adhesives are toxic and the wounds are near sensitive anatomical structures, such as the eye. Still another disadvantage is that adhesives can trap pathogens and other particles within the wound.
Each type of wound closure device and technique has advantages and disadvantages. Sutures pose the risk of injury to the patient caused by the needle as well as to health care professions. The process of suturing also can take a substantial amount of time depending on the size of the wound. Using staples for wound closure is more rapid than suturing, however, unlike sutures, which may be absorbed by the body, staples usually have to be removed by a special tool. Sutures and staples also require applying local anesthesia, which could be dangerous to the patient, especially in the event of an allergic reaction. Furthermore, if the practitioner needs to enter the wound area, the sutures or staples need to be cut or removed, and both sutures and staples can lead to scarring.
Complex wound closure devices that reduce some of these disadvantages have many individual parts, are difficult to apply, or are expensive. Accordingly, it would be advantageous to make available a novel wound closure device that reduces these stated disadvantages and there remains a need for quick and easy to use devices and methods to reapproximate wound edges.